People suffering from movement disorders such as essential tremor and Parkinson's disease can find it difficult to use conventional eating utensils because tremors in their hands cause the utensils to shake. It is estimated that there are about 10 million people who have essential tremor and another one million who have Parkinson's disease. This translates to roughly four percent of the American population. Worldwide, there are an estimated 100 million people with hand tremors.
Some users with hand tremors may use a second hand to grab onto the utensil to reduce the tremor, but this is awkward and may not be very effective.
It may be difficult for a person with a significant hand tremor to bring any eating utensil to the mouth, but it is often particularly difficult to use a spoon both because it may be difficult to get food onto the spoon and because food that is on the spoon may get shaken off. Indeed, at least some prior art anti-tremor spoons may not reduce tremors to a sufficient degree to allow persons with particularly strong tremors to use the spoon without a significant amount of food being shaken off.
Utensils are known in the art that include electronics and/or mechanical components that are intended to reduce the shaking of the utensil. Some such anti-tremor utensils are relative expensive, however, and may require a significant amount of maintenance. Anti-tremor utensils that include electronics, moreover, require battery charging, so that users must remember to have them charged so as to be available for use when desired.
For example, the U.S. patent application of Anupam J. Pathak, 20150300394-A1 published Oct. 22, 2015, discloses an anti-tremor spoon comprising a stabilizing handle and an implement attachment. The stabilizing handle comprises two motors, sensors, and a microcontroller which the Pathak application describes as working together to differentiate tremor motions from the intended motions of the user's hands and to counter the unwanted, tremor motions. This is an “active” device in that its sensors respond to the user's tremor and instruct the motors what to do. Experiments that we have conducted suggest that this spoon reduces tremor by only 70 percent, resulting in a great deal of food still being spilled.
Other known anti-tremor spoons are passive, meaning that in contrast to an active device such as described by Pathak, they only respond to mechanical movement of the hand. One such passive device is the “Steady Spoon” manufactured by Performance Health, as shown at https://www.performancehealth.com/steady-spoontm. This device comprises a handle and a gimbal system that separates the user's tremor motions from the part that lifts the food. Advantages of passive devices are that they may be less expensive to manufacture than active devices and do not require the user to remember to charge them. However, the design of the Steady Spoon is such that a user must hold his/her arm in an uncomfortable position when picking up food. Moreover, we have recognized that it is desirable for an anti-tremor spoon to counter six types of motion—translation along the x-axis, y-axis and z-axis, and rotation about each of those axes. However, the Steady Spoon essentially counters only translation along, and rotation around, the main axis of the device.